9. The displacement is given by x = 2 t^2 + t + 5. The acceleration at t = 2 s is (a) 4 m/s2
(b) 8 m/s2
(c) 10 m/s2
(d) 15 m/s2

4 m/s2

Explanation:

let's find the derivative of x wrt t

x = 2t² + t + 5

dx/dt = 4t + 1

d²x/dt² = 4

the acceleration is 4 m/s²

All of the following devices transmit energy/information: cell phones, walkie talkies, remote controls, and sunlight.

They are all radiation.

I got a 100 on this test.

1. consider the free body diagram. If the sum of the tension forces is equal to the force of gravity, which description BEST applies?

answer. A girl hangs by both hands, motionless, from a trapeze.

2. What causes sea floor spreading ?

answer. Magma.

3. 10 n -> (BOx) <- 20 n Which expression represents the total force on the block ?

answer. 10n =+ -20n.

4. Which waves move by replacing one particle with another?

answer. Sound waves.

5. The table shows dates and appearance of index fossils. Which rock layers can be dated most precisely?

answer. a layer containing both a fossil from 1 and 2

This is an illustration of the ___ moon

answer. new.

hope these help