Question

True or false
1.plastic material regains its orginal shape and size when the deforming force is removed.
2.geothermal energy is a non- renewable energy supply.
3.hook's law states that force applied is directly proportional to the extension of a spring
4.impulse is the product of force and time.
Choose question
A car accelerates from 20m/s to 40m/s in 10sec.what is the distance traveled by the car during the 4th seconds?
A.25m B.27m C.300m D.150m
2.a force of 20N is applied on a body for 6s.what is the impulse on the body?
A.20Ns B.120Ns C.60Ns D.120Ns
3.an object has a final velocity of 10m/s an initial velocity of 5m/s and an acceleration of 3m/s2.calculate the distance covered by this object in its motion.
A.15m B.25m C.12.5m D.1m

Answer 1

1. False
2. False
3. True
4. True

Let us choose the second question:

A force of 20N is applied on a body for 6s. What is the impulse on the body?

Solution

The impulse is

$$p=F\Delta t=20\cdot6=120\text{ N}\cdot\text{s}.$$