How far did a car travel if it was on the road for 55.2s and it traveled at an average speed of 55m/s

maxonik [38]

My personal understanding and opinion is that ALL of those questions
should be part of an assessment of Physical Activity Readiness.

4 0

3 years ago

Read 2 more answers

A brick and a feather fall to the earth at their respective terminal velocities. Which objectexperiences the greater force of ai

Karo-lina-s [1.5K]

Answer:

Under the reasonable assumption that the brick has more mass than the feather, the brick experiences a greater force of air friction.

Explanation:

Objects at terminal velocity, only under the influence of gravity, have maximized their speed and have an acceleration of zero. Thus, neither object is accelerating.

Recall Newton's second law: $\sum {\vec {F}}=m \vec {a}$

Since acceleration for each object is zero, the sum of the force acting on each of those objects must also be zero.

Since the only forces acting on the objects are gravity and the force of air friction, in order to zero out, the force of air friction must be equal in magnitude and opposite in direction to the force of gravity.

Recall that near the surface of the earth, $F_{gravity}=mg$ , so the Force of Gravity acting on an object is directly proportional to the object's mass. (A similar argument could be made even if this were not taking place on the surface of the earth, so long as the objects were the same distance from the object providing gravitational influence).

If the masses of the objects are different, the object with the greater mass will experience a larger force of gravity, and hence a larger force of air friction at terminal velocity.

Under the reasonable assumption that the brick has more mass than the feather, the brick experiences a greater force of air friction.

4 0

2 years ago

If a frictional force of 4 N is acting against a push of 53 N and the box that is being pushed is 4 kg, what is its acceleration

kifflom [539]

Answer:

gggggggggggg

Explanation:

3 0

3 years ago

A playground merry-go-round has radius 2.10m and moment of inertia 2500kg*m^2 about a vertical axle through its center, and it t

vladimir2022 [97]

Answer

Radius of the wheel r = 2.1 m

Moment of inertia I = 2500 Kg m²

Tangential force applied F = 18 N

Time interval t = 16 s

Initial angular speed ω1 = 0

Final angular speed ω2 = ?

Let α be the angular acceleration.

Torque applied τ = Iα

F r = Iα

Angular acceleration α = F r/I

= $\dfrac{18\times 2.1}{2500}$

= 0.015 rad/s²

(a)From rotational kinematic relation

Final angular speed ω₂ = ω₁ + αt

= 0 + (0.015 rad/s^2 * 16 s)

= 0.24 rad/s

(b) Work done W = 0.5 Iω₂² - (1/2)Iω₁²

= 0.5*( 2500 Kg m²)(0.24 rad/s)^2 - 0

= 72 J

(c) Average power supplied by the child P = W/t = $\dfrac{72}{16}$

= 4.5 watt

8 0

3 years ago

A motorcycle is moving at 18 m/s when its brakes are applied, bringing the cycle to rest in 4.7 s. To the nearest meter, how far

morpeh [17]

Answer:

the motorcycle travels 42.4 meters until it stops.

Explanation:

Vi= 18 m/s

Vf= 0 m/s

t= 4.7 sec

Vf= Vi - a*t

deceleration:

a= Vi/t

a= 18m/s / 4.7 sec => a=-3.82 m/s²

x= Vi*t - (a * t²)/2

x= 42.4m

4 0

3 years ago