Help asap please!! An aluminum block of mass 12.00 kg is heated from 20 C to 118 C. If the specific heat of aluminum is 913 J-1

Answer:

The pen requires 7.2 mJ of energy to extend.

Explanation:

Provided:

Length = 1.8 cm

Spring constant = 300 N/m

Initial compression = 1.0 mm

Additional compression = 6.0 mm

Total compression = 1.0 + 6.0 = 7.0 mm

We need to determine the energy needed

This energy is equivalent to the variation in spring potential energy

Substitute the values into the formula

Therefore, a total of 7.2 mJ is needed to extend the pen.

<span>A centripetal force maintains an object's circular motion. When the ball is at the highest point, we can assume that the ball's speed v is such that the weight of the ball matches the required centripetal force to keep it moving in a circle. Hence, the string will not become slack. centripetal force = weight of the ball m v^2 / r = m g v^2 / r = g v^2 = g r v = sqrt { g r } v = sqrt { (9.80~m/s^2) (0.7 m) } v = 2.62 m/s Thus, the minimum speed for the ball at the top position is 2.62 m/s.</span>

Answer:

3.5 cm

Explanation:

mass, m = 50 kg

diameter = 1 mm

radius, r = half the diameter = 0.5 mm = 0.5 x 10^-3 m

L = 11.2 m

Y = 2 x 10^11 Pa

Cross-sectional area of the wire = π r² = 3.14 x 0.5 x 10^-3 x 0.5 x 10^-3

= 7.85 x 10^-7 m^2

Let the change in length of the wire be ΔL.

The equation for Young's modulus is given by

ΔL = 0.035 m = 3.5 cm

Thus, the wire stretches by 3.5 cm.

Answer:

A.

Explanation:

Storing the linens in the closet will prevent them from becoming dirty or contaminated.

Answer:

The change in linear momentum of the ball amounts to 6 kg-m/s.

Explanation:

Provided that,

Ball mass, m = 1 kg

Initial ball speed, u = 3 m/s

Upon striking a wall, it rebounds, moving horizontally to the opposite side at the same speed of 3 m/s, thus v = -3 m/s

The change in linear momentum is calculated as follows:

Consequently, the magnitude of the change in linear momentum of the ball is 6 kg-m/s.