Answer:
Explanation:
In order to measure the coefficient of friction , we apply external force to move the body . When external force comes in motion , we adjust the external force so that it moves with zero acceleration or uniform velocity . In this case external force becomes equal to kinetic frictional force and then net force becomes zero because
net force = mass x acceleration = m x 0 = 0
Now frictional force = μ mg where μ is coefficient of kinetic friction
so F = μ mg where F is external force applied
μ = F / mg
Hence , to make external force equal to frictional force , it is necessary to make acceleration of body zero .
Answer:
D. 12.4 m
Explanation:
Given that,
The initial velocity of the ball, u = 18 m/s
The angle at which the ball is projected, θ = 60°
The maximum height of the ball is given by the formula
h = u² sin²θ/2g m
Where,
g - acceleration due to gravity. (9.8 m/s)
Substituting the values in the above equation
h = 18² · sin²60 / 2 x 9.8
= 18² x 0.75 / 2 x 9.8
= 12.4 m
Hence, the maximum height of the ball attained, h = 12.4 m
Answer:
Explanation:
She's correct but doesn't mean the wagon cannot put into motion. The force that she applied on the wagon, according to Newton's 2nd law, would have generated an acceleration, which translates into motion. The reaction force the wagon applies on her due to Newton's 3rd law, would not hinder its own motion.
Answer:
Seismic waves cause Earthquakes by shaking the ground aggressively and dangerously. These waves are usually calculated on a seismograph to calculate how hard the earthquake hit that area. A transform Boundary creates the tension when the tectonic plates gets stuck. It stays stuck for a long period of time. Then, at one point, the tectonic plates become unstuck which releases the tension into waves which are called seismic waves. Hope I answered you question.
Answer:
Speed at which it will reach the ground is given as
Total time for which it will remain in air is given as
t = 6.3 s
Explanation:
As we know that the object is projected upwards with speed
now when it will reach the ground then we have
so we have
so we have
Now speed of the object when it reaches the ground is given as