1) velocity: 98 m/s downward
Explanation:
The marble moves by uniformly accelerated motion, with constant acceleration a=g=-9.8 m/s^2 directed towards the ground. Therefore, its velocity at time t is given by:
where
is the initial velocity
is the acceleration
is the time
Substituting t = 10 s, we find:
And the negative sign means the direction of the velocity is downward.
2) Distance covered: 490 m
The distance covered in an uniformly accelerated motion can be found with the formula:
where
is the acceleration
t is the time
Substituting t=10 s, we find
And the negative sign means the displacement is below the dropping point.
What's the weight of the pear ?
Weight = (mass) x (gravity) = (1 kg) x (9.8 m/s²) = 9.8 Newtons.
OK. We know there's a force of 9.8 Newtons acting downwards on the pear.
Is the pear accelerating ? No ! It's just laying there on the table.
If it's not accelerating, then we know that the net force on it must be zero.
So there must be ANOTHER force acting UPWARDS on it, to exactly
cancel out the downward force of its weight. THAT's the "normal" force ...
the upward force that the table exerts on the pear. It must also be 9.8N,
but UPwards, so that if you add it to the weight, the sum is zero.
Answer:
0. 3 s
Explanation:
The motion of the boat is up and down in simple harmonic with amplitude of 20 cm . Time period of oscillation T = 3.5 s and top extreme point is at level with the boarding dock .
The traveller has to wait until the boat reaches middle point ( 1o cm . ) that is half its equilibrium position of oscillation .
Time period is 3.5 s . During its oscillation from extreme top position to its half of the equilibrium position , that is 10 cm below the stationary dock , time taken by boat
t = T / 12 = 3.5 /12 = .3 s .
Man shall have to wait for a period of 0.3 s
Ans 0. 3 s .
The answer that you are looking for is D.
Answer:
geothermal energy
Explanation:
the energy is obtained from the heat within the surface of earth