Question

force-time graph of 2kg mass starts from rest is given. find speed at t=1s​

Answer 1

Answer:

Correct option is

A

7.5

As we know that Force F=

dt

dP

​

, P is momentum so dP=Fdt where dP is change in momentum due to force F

In other words the momentum imparted by force will be given by the area under the F−t graph

so ΔP=area=smaller rectangle + larger vertical rectangle =10N×(0.5−0)s+20N×(1.0−0.5)s

or ΔP=15Ns

so the velocity change is Δv=

mass

15Ns

​

=7.5m/s

as the mass started from mass so new velocity will be 7.5m/s

Explanation: