C. a cello playing music at the concert
Answer:
3.88m/s
Explanation:
Using the law of conservation of momentum
m1u1+m2u2 = (m1+m2)v
m1 and m2 are the masses
u1 and 2 are the initial velocities
v is the final velocity
Given
m1 = 64kg
u1 = 4.2m/s
m2 = 25kg
u2 = 3.2m/s
Required
Final velocity v
Substitute the given values into the formula
64(4.2)+25(3.2) = (65+25)v
268.8+80 = 90v
348.8 = 90v
v = 348.8/90
v = 3.88m/s
Hence the velocity of the kayak after the swimmer jumps off is 3.88m/s
The weight of the box is 50x9.8 = 490 N. The force of friction is 100N. F= μΝ so coefficient = 100/490 = 0.20
Velocity = distance / time
v = (15*1000)m / (2*60*60)s
v=2.08 m / s
Answer:
4.44 rpm
Explanation:
= Angular speed
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
r = Radius of Europa = 
R = Radius of arm = 6 m
The acceleration due to gravity is given by

Here the centripetal acceleration of the arm and acceleration due to gravity are equal


Converting to rpm


The angular speed of the arm is 4.44 rpm