A snail moves 40 cm in 20 seconds. How fast did it move?

If this decay has a half-life of 10.2 years, what mass of 60.8g carbon-14 will remain after 20.4 years

OLEGan [10]

20.4 years is 20.4/10.2 = 2 half-life cycles, which means a quarter of the starting mass or 15.2 g will remain after this time.

5 0

2 years ago

Scientific theories have strod the test of time and will not change

Nataly [62]

That is not a question but not all scientific theories have stood the test of time

8 0

3 years ago

A 5.00X10^5 kg rocket is accelerating straight up. Its engines produce 1.250X10^7 N of thrust, and air resistance is 4.50X10^6 N

katrin [286]

6.20 m/s^2 The rocket is being accelerated towards the earth by gravity which has a value of 9.8 m/s^2. Given the total mass of the rocket, the gravitational drag will be 9.8 m/s^2 * 5.00 x 10^5 kg = 4.9 x 10^6 kg m/s^2 = 4.9 x 10^6 N Add in the atmospheric drag and you get 4.90 x 10^6 N + 4.50 x 10^6 N = 9.4 x 10^6 N Now subtract that total drag from the thrust available. 1.250 x 10^7 - 9.4 x 10^6 = 12.50 x 10^6 - 9.4 x 10^6 = 3.10 x 10^6 N So we have an effective thrust of 3.10 x 10^6 N working against a mass of 5.00 x 10^5 kg. We also have N which is (kg m)/s^2 and kg. The unit we wish to end up with is m/s^2 so that indicates we need to divide the thrust by the mass. So 3.10 x 10^6 (kg m)/s^2 / 5.00 x 10^5 kg = 0.62 x 10^1 m/s^2 = 6.2 m/s^2 Since we have only 3 significant figures in our data, the answer is 6.20 m/s^2

8 0

3 years ago

A video store owner noticed a 5% drop in rentals of DVDs after raising her prices 10%. Are DVD rentals

lukranit [14]

Answer:

Inelastic

Explanation:

The price elasticity of demand is the degree of responsiveness of demand for a product or service to a unit change in price. The demand for a product is said to be elastic when a change in price has a relatively large effect on the demand for the product, unitary when there is a percentage change in price brings about an equal percentage change in the demand for the product, and inelastic when a change in the price of a product brings about a smaller change in the demand for the product.

In the case of the DVD rentals, a 10% increase in price brought about only a 5% drop in demand. Hence, the demand for DVD rentals is said to be inelastic because a change in the price brought about a smaller change in the demand for DVD rentals.

8 0

2 years ago

if you drop a softball from just above your knee, the kinetic energy of the ball just before it hits the ground is about 1 jule,

ipn [44]

False.

The mass of a softball is approximately 200 g (0.2 kg), while the knees are located approximately at 30 cm (0.3 m) from the ground. It means that the gravitational potential energy of the ball when it is dropped is
$U=mgh=(0.2 kg)(9.81 m/s^2)(0.3 m)=0.6 J$

This corresponds to the total mechanical energy of the ball at the moment it is dropped, because there is no kinetic energy (the ball starts from rest). Then the ball is dropped, and just before it hits the ground, all this energy is converted into kinetic energy: but energy cannot be created, so its final kinetic energy cannot be greater than 0.6 J.

7 0

3 years ago