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2 years ago

If a ball speeds up as it is rolling down a hill, the forces acting on it must be -

Physics

1 answer:

VMariaS [17]2 years ago

3 0

Answer:

the forces acting on it must be strong because gravity is pushing the ball down

Explanation:

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A horizontal metal bar oriented east-west drops straight down in a location where the earth's magnetic field is due north. as a

amid [387]

Metal bar is aligned along East- West direction and it is dropped vertically down

So its velocity is along -Z direction,

Now the Earth's magnetic field is towards north so its towards +Y direction

now we have formula for force on a moving charge

$F = q(v X B)$

v = - z direction

B = + y direction

now by the above formula

$F = q(v(-k) X B(j))$

$F = qvB (i)$

So force is towards East

so all positive charge is towards East end

5 0

2 years ago

According to Archimedes’ principle, the mass of a floating object equals the mass of the fluid displaced by the object. Use this

Andrew [12]

Answer:

Part a)

$\rho = 0.55 g/cm^3$

Part b)

$\rho_L = 1.49 g/cm^3$

Part c)

Since we know that the base area will remain same always

so here the length and width of the object is not necessary to obtain the above data in such type of questions

Explanation:

Part a)

As we know that when cylinder float in the water then weight of the cylinder is counter balanced by the buoyancy force

So here we know

buoyancy force is given as

$F_b = \rho_w V_{sub} g$

$F_b = (1 g/cm^3) (30 - 13.5) Ag$

$F_b = 16.5 Ag$

Now we know that the weight of the cylinder is given as

$W = \rho (30 cm)A g$

now we have

$\rho (30 cm) A g = 16.5 A g$

$\rho = 0.55 g/cm^3$

Part b)

When the same cylinder is floating in other liquid then we will have

$F_b = \rho_L (30 - 18.9 )A g$

so we have

$\rho_L (11.1) Ag = 0.55(30) Ag$

$\rho_L = 1.49 g/cm^3$

Part c)

Since we know that the base area will remain same always

so here the length and width of the object is not necessary to obtain the above data in such type of questions

3 0

2 years ago

A 72.0-kg skydiver is falling at a terminal velocity of 79.0 m/s. Which equation should be used to calculate the diver’s kinetic

rodikova [14]

Answer:

KE= 1/2 * mass * Velocity^2

Explanation:

1/2 * 72.0kg* 79^2 m/s = 224676 J

4 0

2 years ago

A sock with a mass of 0.03 kg is stuck to the inside of a clothes dryer spins

ValentinkaMS [17]

Answer:

15.71 m/s

Explanation:

We are given;

Time; t = 0.2 s

Radius; r = 0.5 m

The circumference will give us the distance covered.

Formula for circumference is 2πr

Thus; Distance = 2πr = 2 × π × 0.5 = π

Linear speed = distance/time = π/0.2 = 15.71 m/s

5 0

3 years ago

During the push-up, the hips should never hit the ground and should move 1 point

Monica [59]

Hahahahahahahahahha true

4 0

2 years ago