1.
How many metres in one kilometre?
Correct Answer
C. 1000
Explanation
There are 1000 meters in one kilometer. This is a standard conversion in the metric system, where the prefix "kilo-" represents a factor of 1000. Therefore, when converting from kilometers to meters, you multiply the value by 1000.
2.
What is the acceleration due to gravity (in ms^{-2})?
Correct Answer
10
9.8
Explanation
The acceleration due to gravity is a constant value that represents the rate at which objects fall towards the Earth. In this case, the given answer includes two options: 10 and 9.8. The correct answer is 9.8, as it is the standard value for the acceleration due to gravity on Earth, usually rounded to 9.8 m/s^2. The option 10 is incorrect as it does not accurately represent the value of the acceleration due to gravity.
3.
The slope of a distance time graph gives us _______________ of an object.
Correct Answer
A. Speed
Explanation
The slope of a distance-time graph represents the change in distance over time. In other words, it shows how fast an object is moving. Therefore, the correct answer is speed.
4.
A car travelling at 10ms^{-1}for 2 minutes covers a distance of _________________ metres.
Correct Answer
1200
Explanation
The car is travelling at a constant speed of 10 m/s for 2 minutes. To find the distance covered, we need to multiply the speed by the time. Since 1 minute is equal to 60 seconds, the total time in seconds is 2 minutes x 60 seconds/minute = 120 seconds. Therefore, the distance covered is 10 m/s x 120 seconds = 1200 meters.
5.
The slope a speed - time graph gives us the _______________ of the object
Correct Answer
C. Acceleration
Explanation
The slope of a speed-time graph gives us the rate at which the speed is changing over time, which is the definition of acceleration. Therefore, the correct answer is acceleration.
6.
A mass of 3 kg is initially at rest. It accelerates at a rate of 4ms^{-2 }. Calculate its speed after 5 seconds of acceleration.
Correct Answer
D. 20
Explanation
The speed of an object can be calculated using the formula v = u + at, where v is the final velocity, u is the initial velocity (which is 0 in this case since the object is initially at rest), a is the acceleration, and t is the time. Plugging in the given values, v = 0 + (4 m/s^2)(5 s) = 20 m/s. Therefore, the speed of the object after 5 seconds of acceleration is 20 m/s.
7.
A mass of 2 kg is initially moving at a steady speed of 3 ms^{-1}. It then accelerates at a rate of 2ms^{-2 }. Calculate its speed after accelerating for 4 seconds.
Correct Answer
A. 11
Explanation
The initial speed of the mass is 3 m/s and it accelerates at a rate of 2 m/s^2 for 4 seconds. To calculate the final speed, we can use the formula: final speed = initial speed + (acceleration * time). Plugging in the values, we get: final speed = 3 + (2 * 4) = 3 + 8 = 11 m/s. Therefore, the correct answer is 11.
8.
A mass of 2 kg is initially moving at a steady speed of 3 ms^{-1}. It then accelerates at a rate of 2ms^{-2 }. Calculate the distance it covers during the first 4 seconds of its acceleration
Correct Answer
E. 28
Explanation
The distance covered during the first 4 seconds of acceleration can be calculated using the equation: distance = initial velocity * time + 0.5 * acceleration * time^2.
Given that the initial velocity is 3 m/s, the time is 4 seconds, and the acceleration is 2 m/s^2, we can substitute these values into the equation to find the distance.
distance = 3 * 4 + 0.5 * 2 * (4^2) = 12 + 0.5 * 2 * 16 = 12 + 16 = 28.
Therefore, the correct answer is 28.
9.
What force(s) are acting on a ball as it is moves vertically up in the air?
Correct Answer
D. Gravity and Air Resistance
Explanation
As the ball moves vertically up in the air, two forces are acting on it. Gravity is pulling the ball downwards, trying to bring it back to the ground. At the same time, air resistance is acting on the ball, pushing against its motion and slowing it down. Therefore, the correct answer is gravity and air resistance.
10.
What does the area underneath the curve of a speed - time graph represent?
Correct Answer
B. Distance
Explanation
The area underneath the curve of a speed-time graph represents distance. This is because the area under the curve represents the displacement of an object over a given time interval. In the context of a speed-time graph, the area under the curve represents the distance traveled by the object during that time interval. Therefore, the correct answer is distance.