Answer: a all the outer planets are large
Explanation: because i have the smarts
Answer:
a. -369.36J
b. -123.9J
c. 9.52m
Explanation:
From the expression for kinetic energy
K. E=1/2mv^2
Since the mass is constant, but the velocity changes. Hence the change in kinetic energy is
K.E=1/2*19(3.6²-7.2²)
K.E= -369.36J
b. to determine the workdone by the force,we determine the distance moved.
But the acceleration is from
F=ma ,
a=f/m
a=-13/19
0.68m/s²
the distance moved is
s=v²/2a
s=3.6²/2*0.68
s=9.52m
Hence the work done is
W=force * distance
W=-13*9.52
W=-123.9J
d. the distance moved is
s=v²/2a
s=3.6²/2*0.68
s=9.52m
Answer:
<u><em>A. wavelength</em></u>
Explanation:
The others are about sound and how high it is. That has nothing to do with time.
#14 isn't really a Physics problem. It's more of just reading a graph.
A). When speed changes, acceleration is
(change in speed) / (time for the change) .
To be correct about it, acceleration can be positive ... when speed
is increasing ... or it can be negative ... when speed is decreasing.
So, on this graph, there are two periods of acceleration:
From zero to 2 seconds, acceleration = (8 m/s) / (4 sec) = 2 m/s² .
From 10 to 12 seconds, acceleration = (-4 m/s) / (2 sec) = -2 m/s² .
B). From 12 to16 seconds, you can read the speed right from
the graph. It's 4 m/s .
C). From 2 to 10 seconds, the objects speed is a steady 8 m/s.
Covering 8 m/s every second for 8 seconds, it covers 64 meters.
Do you remember that distance is the area under the speed/time
graph? You can see that plainly on this graph. From 2 to 10 sec,
there are 16 blocks. Each block is (2 m/s) high and (2 sec) wide,
so its area is (2 m/s) x (2 sec) = 4 meters. The area of 16 blocks
is (16) x (4 meters) = 64 meters.
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#15.
a). constant velocity on a distance graph is a line that slopes up;
constant velocity on a velocity graph is a horizontal line;
b). positive constant acceleration on a distance graph is a
line that curves up;
positive constant acceleration on a velocity graph is a
straight line that slopes up;
c). "uniformly slowing down to a stop" on a distance graph
is a line that's less and less curved as time goes on, and
eventually reaches the x-axis.
"uniformly slowing down to a stop" on a velocity graph is
a straight line that slopes down, and stops when it reaches
the x-axis.
Answer:
The average force the golf club exerts on the ball is 600 N
Explanation:
Newton's second law of motion states that force, F, is directly proportional to the rate of change of momentum produced
F = m× (v₂ - v₁)/(Δt)
The given parameters of the motion of the ball are;
The mass of the ball, m = 45 g = 0.045 kg
The initial velocity of the ball, v₁ = 0 m/s
The speed with which the ball was hit by the golfer, v₂ = 40 m/s
The duration of contact between the golf club and the ball, Δt = 3 ms = 0.003 seconds (s)
By Newton's law of motion, the average force, 'F', which the golf club exerts on the ball is therefore, given as follows;
F = 0.045 kg × (40 m/s - 0 m/s)/(0.003 s) = 600 N
The average force the golf club exerts on the ball = F = 600 N.
