Answer:
1) Given acceleration due to gravity as 10N/kg
N/kg is the same as m/s². From W=mg
making g subject ... you have g = W/m
where m is in kg and W is in N
hence we have N/kg
So g=10ms-²
Gravitational Potential Energy=mgh
At height 4m
PE=6 x 10 x 4
=240J.
At height 6m
PE=6 x 10 x 6
=360J.
2) KE=1/2mv²
=1/2 x 6 x 5² =75J
When the speed is doubled... it becomes 2x
so V = 2x5=10ms-¹
KE=1/2 x 6 x 10² =300J.
3) KE=1/2mv²
KE is given as 100J
mass=0.5kg
Making V the subject
you have v² =2KE/m
v²=2 x 100/0.5
v²=400
taking square root
v=20ms-¹.
Have a great day✌
Answer:
A. Repeat the experiment to be sure the results are valid.
Food causes the response (salivation). Pair the food each time with a cell phone ringing. Continue this process with repetition.
• Eventually, the rabbit will learn to salivate at the ringing
Answer:
94.13 ft/s
Explanation:
<u>Given:</u>
= time interval in which the rock hits the opponent = 10 s - 5 s = 5 s
= distance to be moved by the rock long the horizontal = 98 yards
= displacement to be moved by the rock during the time of flight along the vertical = 0 yard
<u>Assume:</u>
= magnitude of initial velocity of the rock
= angle of the initial velocity with the horizontal.
For the motion of the rock along the vertical during the time of flight, the rock has a constant acceleration in the vertically downward direction.

Now the rock has zero acceleration along the horizontal. This means it has a constant velocity along the horizontal during the time of flight.

On dividing equation (1) by (2), we have

Now, putting this value in equation (2), we have

Hence, the initial velocity of the rock must a magnitude of 94.13 ft/s to hit the opponent exactly at 98 yards.