A would be most useful (Carbon dating)
Answer:
It will take you 30.8 s to travel the 120 m of the ramp.
Explanation:
Hi there!
The equation for the position of an object moving in a straight line is:
x = x0 + v * t
Where:
x = position at time t
x0 = initial position
v = velocity
t = time
In this case, we will consider the start of the ramp as the origin of our reference system so that x0 = 0.
Now, let´s calculate the speed of the person walking on the ground:
x = v * t
120 m = v * 72 s
v = 120 m / 72 s
v = 1.7 m/s
If you walk on the ramp with that speed, your total speed will be your walking speed plus the speed of the ramp because both are in the same direction. Then, using the equation for the position:
x = v * t
In this case, v = speed of the ramp + walking speed
v = 2.2 m/s + 1.7 m/s = 3.9 m/s
120 m = 3.9 m/s * t
t = 120 m / 3.9 m/s = 30.8 s
It will take you 30.8 s to travel the 120 m
Answer:
option B
Explanation:
given,
Force exerted by the hydraulic jack piston = F₁ = 250 N
diameter of piston, d₁ = 0.02 m
r₁ = 0.01 m
diameter of second piston, d₂ = 0.15 m
r₂ = 0.075 m
mass of the jack to lift = ?
now,
F₂ = 14062.5 N
F = m g
m = 1435 Kg
hence, the correct answer is option B
Answer:
The Physical Behavior of Objects when Gravity is Missing
In order to be able to form a concept of the general physical conditions existing in a weightless state, the following must be noted: the force of the Earth's gravity pulling all masses down to the ground and thus ordering them according to a certain regularity is no longer active.
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.
