Question

A) A runner begins to run from rest and it takes him 10.4 meters to speed up to a speed of 12m/s. What is this runner's acceleration?

B) What is the final speed of an object dropped from rest at a height of 120m?

C) What would the final speed of a mass sliding through a 32m frictionless incline of 24 degrees be?

D) What is the range of a projectile shot horizontally at a height of 46m with a speed of 15m/s?

E) For the initial velocity vector v>=10x^+8y^, find a) the direction angle, b) the speed c) the range if this is the initial speed vector for a projectile with a full parabolic trajectory.

Answer 1

A) u = initial speed = 0

s = distance covered = 10.4 m

final speed = 12 m/s

a = acceleration = ?

using kinematic equation :

[answer]

B) u = initial speed = 0

h = height traevlled = 120m

a = 9.81 m/s^2

v = final speed = ?

using kinematic equation :

[answer]

C) u = initial speed = 0

v = final speed = ?

distance travelled along inclined plane = 32 m

angle of inclination = theta = 24 degree

a = acceleration = g* sin(24 degree)

using kinematic equation :

[answer]

D) horizontal speed = v = 15 m/s

initial vertical speed = 0

height = h = 46 m

R = horizontal range

using kinematic equation for vertical motion :

horizontal distance travelled in the time t is = R = vt = 15*3.06 = 45.9 m [answer]

E) initial velocity vector =

a) angle of prjectile with horizontal = [answer]

b) speed = v = [answer]

c) horizontal range = R = [answer]