Answer:
Explanation:
v = u +at
u = 0
a = 2.3 m /s²
t = 20 s
v = 2.3 x 20
= 46 m /s
Distance covered under acceleration of 2.3 m/s²
s = ut + 1/2 at²
= 0 + .5 x 2.3 x 20²
= 460 m
After that it moves under free fall ie g acts on it downwards .
v² = u² - 2gh , h is height moved by it under free fall
0 = 46² - 2 x 9.8 h
h = 107.96 m
Total height attained
= 460 + 107.96
= 567.96 m
b ) At its highest point ,it stops so its velocity = 0
c ) rocket's acceleration at its highest point = g = 9.8 downwards .
At highest point , it is undergoing free fall so its acceleration = g
static electricity and friction
Answer
given,
mass of ball, m = 57.5 g = 0.0575 kg
velocity of ball northward,v = 26.7 m/s
mass of racket, M = 331 g = 0.331 Kg
velocity of the ball after collision,v' = 29.5 m/s
a) momentum of ball before collision
P₁ = m v
P₁ = 0.0575 x 26.7
P₁ = 1.535 kg.m/s
b) momentum of ball after collision
P₂ = m v'
P₂ = 0.0575 x (-29.5)
P₂ = -1.696 kg.m/s
c) change in momentum
Δ P = P₂ - P₁
Δ P = -1.696 -1.535
Δ P = -3.231 kg.m/s
d) using conservation of momentum
initial speed of racket = 0 m/s
M u + m v = Mu' + m v
M x 0 + 0.0575 x 26.7 = 0.331 x u' + 0.0575 x (-29.5)
0.331 u' = 3.232
u' = 9.76 m/s
change in velocity of the racket is equal to 9.76 m/s
Pressure is the amount of force exerted on an object and force is strength or energy of an action
