Answer:
RIGHT
Explanation:
given,
mass of box = 250 kg
speed of the truck = 25 m/s
static friction µs = 0.7
g = 10 m/s²
to find direction of friction on the box
truck is moving in left direction and suddenly in front of truck a car stops then the driver hit the brake hard so at that moment the box on the trailer will have the tendency to move left so to oppose its movement friction force will be on RIGHT
Take gravity you are accelerated toward the ground. Since gravity has both a direction and a magnitude, then it is a vector.
<span>equal-arm balance = 12 kg
spring scale = 2 kg
The equal arm balance measures the mass of an object by using a counter mass on the opposite plate of the balance. The force of gravity affects both the mass being tested and the mass standards being compared against equally. So if the local gravitational field changes, those changes affect both the tested mass and the standard masses equally.
Contrast that to the spring scale. In that scale, the spring provides a calibrated level of force irrespective of the local gravitational field. So if the local gravity is higher, the force indicated also is higher. And if the gravitational field is lower, the indicated force is also lower. The strength of the spring DOES NOT CHANGE with changes in the local gravitational field.</span>
C. This is the idea of "black body radiation". Charcoal/carbon is a "perfect black body". Absorbs all radiation. There's a whole host of stuff about this in physics, including, I think, Planck's (Nobel Prize winner) black body radiation theory.
Given:
speed of passing pony 5 m/s
frequency of the sound produced: 221 Hz
speed of sound 342 m/s
Let us use the Doppler Shift Formula:
Where the <span>source is moving away from the observer at rest
</span>
f' = (v / v+vs) f
Where, vs<span> = Velocity of the Source,</span>
v = Velocity of sound or light in medium,
f = Real frequency,
f' = Apparent frequency.
f'= [342 m/s / (342 m/s+5m/s)] * 221 Hz
f' = 0.9856 * 221Hz
f' = 217.8176 Hz or 218 Hz
The observed frequency <span>of the hooves after the pony has passed your position is 218 Hz.</span>
