A boy throws a ball with a velocity of 30m/s. Find the total tome elapsed between throwing and catching the ball (take g=10m/s2)

x=45.92m

Explanation:

It's a pretty simple suvat linear projectile motion question, using the following equation and plugging in your values it's a pretty trivial calculation.

V^2=U^2+2*a*x

V=0 (as it is at max height)

U=30ms^-1 (initial speed)

a=-g /-9.8ms^-2 (as it is moving against gravity)

x is the variable you want to calculate (height)

0=30^2+2*(-9.8)*x

x=-30^2/2*-9.8

x=45.92m

With these questions it's best to just memorise the suvat equations and either draw or imagine the actions involved, that was you can tell what piece of given information translates to which variable. For example; I know that I am looking for max height, so when a ball is at its highest point, it can't be moving up anymore (thus V = 0). I also know that it is moving upwards against gravity, so gravity will be decelerating the ball (therefore a=-g). In a paper, it may as for assumptions with this question, a good answer would be no air resistance or movement due to any other external forces. I hope I helped :)

By applying the law of conservation of energy, we can write the following equation.

Gain in potential energy =loss in kinetic energy.

mgh = 1/2(mu^2)

Where, the symbols represent usual quantities.

Hence, h = u^2/2g = 30^2/2x10 = 900/20

= 45 m

Hence, the maximum height attained is 45 m.

Alternative method:

v^2 = u^2 +2gh

0 = 30^2 +2(-10)h, at the highest point v=0

20h = 900

h = 900/20 = 45 m

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min

the correct answer to the question is it has inertia.

explanation:

the splashing of water in the bottle can be explained in terms of inertia of motion.

from newton's first law of motion, we know that a body moving with uniform velocity along a straight line will keep on moving with the same velocity along that line unless and until it is compelled by some external unbalanced force. it is known as inertia of motion.

as per the question, the passenger is in the moving car. the open water bottle has the same velocity as that of passenger as he is holding the bottle.

when the car stops, the passenger will move in forward direction due to the inertia of motion. same also happens in case of water present in the bottle. the water splashed out as its inertia of motion is destroyed .