Which is not expecting acceleration?
1 answer:
#1
A point on the outside of a spinning top whose rotational speed is constant.
Since the point at the top is at rest so it will not accelerate at all
A skydiver whose air resistance is equal to that of her weight.
Since weight is counter balanced by air resistance so net force on it is zero so acceleration will be zero
A car on the freeway experiencing a net force of -120 N.
Since net force is not zero so it will accelerate here
A submerged beach ball whose buoyant force is eight times the force of gravity on it.
Since buoyant force is more than the weight so it will not at rest and move upwards with some acceleration
#2
A frictionless spinning merry go round.
Since spinning wheel accelerating due to centripetal force so it is non inertial frame
A falling rock.
Falling rock is accelerating due to gravity so it is again non inertial frame
A hot air balloon moving at 30 degrees east of north with no net force.
since hot air balloon is having no force on it so its acceleration is zero and its an inertial frame
A space shuttle whose boosters just ignited for takeoff.
Since space shuttle is accelerating due to boosters so it is non inertial frame
#3
Here net force on it is due to two given forces
towards right
towards left
so here net force is given as
since force towards left is more so the direction will be towards left
so correct answer is 60 N towards left
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The catcher can catch the ball at a height of 0.96 m from the ground.
The distance between the pitcher's mound and the catcher's box is about 60'6", which translates to 18.44 m. An average pitcher can pitch with speeds ranging from 88 mph to 97 mph, which is from 39.3 m/s to 43.4 m/s.
Assume the pitcher pitches a ball horizontally with a speed of 40 m/s. If the catcher catches the ball in a time t, then the ball travels a horizontal distance x of 18.44 m and at the same time falls through a height y.
The horizontal motion of the ball is uniform motion since no force acts on the ball ( assuming no air resistance) and hence the acceleration of the ball along the horizontal direction is zero.
Therefore,
Calculate the time t by substituting 18.44 m for x and 40 m/s for u.
The ball is acted upon by the earth's gravitational attraction and hence it accelerates downwards with an acceleration equal to the acceleration due to gravity g.
Since a horizontal projection is assumed, the ball has no component of velocity in the downward direction.
Therefore, for vertical motion, which is an accelerated motion, the distance y, the ball falls in the time t taken by it to reach the catcher's box is given by the equation,
Substitute 9.8 m/s² for g and 0.461 s for t.
The pitcher releases the ball at a height of 1.8 m from a mound which is at a height of 0.2 m. Thus, the ball is released at a height of 2.0 m from the ground. It falls through a distance of 1.04 m in the time it takes to reach the catcher.
Therefore, the height at which the catcher needs to keep his glove so as to catch the ball is given by,
The catcher needs to hold his glove at a height of <u>0,96 m from the ground.</u>
Answer:
v = 9.936 m/s
Explanation:
given,
height of cliff = 40 m
speed of sound = 343 m/s
assuming that time to reach the sound to the player = 3 s
now,
time taken to fall of ball
t = 2.857 s
distance
d = v x t
d = v x 2.875
time traveled by the sound before reaching the player
distance traveled by the wave in this time'
r = 0.143 x 343
r= 49.05 m
now,
we know.
d² + h² = r²
d² + 40² = 49.05²
d =28.387 m
v x 2.875=28.387 m
v = 9.936 m/s