When an elevator is accelerating downward, the normal force is equal to mg-ma (hence you feel a little lighter when accelerating downwards)
Therefore, the upward force of the elevator floor on the person must be less than 750N
It is a stretch of the atmosphere ranging from the upper mesosphere to the lower parts of the thermosphere. It’s useful to us in radio communication.
Answer:
A
Explanation:
if he goes to the west, the east is opposite so 100-30
Explanation:
Assuming the wall is frictionless, there are four forces acting on the ladder.
Weight pulling down at the center of the ladder (mg).
Reaction force pushing to the left at the wall (Rw).
Reaction force pushing up at the foot of the ladder (Rf).
Friction force pushing to the right at the foot of the ladder (Ff).
(a) Calculate the reaction force at the wall.
Take the sum of the moments about the foot of the ladder.
∑τ = Iα
Rw (3.0 sin 60°) − mg (1.5 cos 60°) = 0
Rw (3.0 sin 60°) = mg (1.5 cos 60°)
Rw = mg / (2 tan 60°)
Rw = (10 kg) (9.8 m/s²) / (2√3)
Rw = 28 N
(b) State the friction at the foot of the ladder.
Take the sum of the forces in the x direction.
∑F = ma
Ff − Rw = 0
Ff = Rw
Ff = 28 N
(c) State the reaction at the foot of the ladder.
Take the sum of the forces in the y direction.
∑F = ma
Rf − mg = 0
Rf = mg
Rf = 98 N
The velocity of the stuntman, once he has left the cannon is 5 m/s.
The right option is O A. 5 m/s
The Kinetic energy of the stuntman is equal to the elastic potential energy of the spring.
<h3 /><h3>Velocity: </h3>
This is the ratio of displacement to time. The S.I unit of Velocity is m/s. The velocity of the stuntman can be calculated using the formula below.
⇒ Formula:
- mv²/2 = ke²/2
- mv² = ke².................. Equation 1
⇒ Where:
- m = mass of the stuntman
- v = velocity of the stuntman
- k = force constant of the spring
- e = compression of the spring
⇒ Make v the subject of the equation
- v = √(ke²/m)................. Equation 2
From the question,
⇒ Given:
- m = 48 kg
- k = 75 N/m
- e = 4 m
⇒ Substitute these values into equation 2
- v = √[(75×4²)/48]
- v = √25
- v = 5 m/s.
Hence, The velocity of the stuntman, once he has left the cannon is 5 m/s.
The right option is O A. 5 m/s
Learn more about velocity here: brainly.com/question/10962624
