Question

please answer the first three question ​

Answer 1

Answer:

24 $m/s^2$, (1.6 $m/s^2$, 3.2 $m/s^2$) , 4 m/s

Explanation:

First, you have to understand the concept related to the question. Here, one formula: F = ma , is enough to solve the first three questions.

Take 1st question:

`1.)

     Mass of the body is 12 kg, acceleration is 2 $m/s^2$. Force is the product of mass and acceleration, which is 12 x 2 = 24 $m/s^2$.

2.)

     Here, force and mass is given, they are asking acceleration. Same formula: F = ma : 80 = 50 a : a = 8/5 $m/s^2$ = 1.6 $m/s^2$

If mass is halved, then acceleration will double as: a = F/m, as m decreases, a increases. So acceleration will become 1.6 x 2 = 3.2 $m/s^2$

3.)

     For the third question, you have to understand that since force is acting, acceleration will act. Acceleration is just rate of change of velocity, which means 'how much velocity will change per second'. So you have to subtract final and initial velocity and then divide it by time to find acceleration.

First find acceleration initially:

u = 1.8 m/s, v = 4.2 m/s, t = 1.2 seconds

a = (v - u)/t = 2.4/1.2 = 2 $m/s^2$

This same acceleration will be applied after two seconds, when its initial velocity will be 4.2 m/s for two seconds.

So later, u = 4.2 m/s, a = 2 $m/s^2$, t =2

Using equation of motion: v = u + at:

v = 4.2 + 2(2) = 4.2 + 4 = 8.2 m/s

Speed change will be 8.2 - 4.2 = 4 m/s

Hope it helps!